1. Field of the Invention
The present invention relates to machines and methods for harvesting food crops, and more particularly, to an improved small-scale machine and related methods for separating larger volumes of vine-borne crops from their vines while effectively removing unwanted dirt, vegetation and debris, minimizing damage to the fruit itself, and promoting better sorting of fruit.
2. Description of the Prior Art
Vine-borne crops have traditionally been harvested and processed by hand. However, such manual harvesting and processing was often tedious, time-consuming and expensive.
Various machines, such as the one disclosed in U.S. Pat. No. 6,033,305, have been developed over the years to automate part, or all, of this process. These machines are able to harvest vine-borne crops from the ground at much faster speeds than humans. However, these machines were often inefficient in other aspects of the harvesting process. Early harvesting machines severed entire plants and dropped them upon the ground, with the desired crops remaining affixed to the plants. Then, collection devices would retrieve the mixture of vegetation, dirt and debris for processing. Human sorters would then be required to sort through the mixture to separate the crops from the rest, and extract the former. The human sorters had to quickly process these mixtures to prevent a backlog. As a result, some suitable crops were lost because they were too far entangled within the plants, or simply overlooked by the human sorters.
Various devices have been developed over the years to improve the mechanized harvesting process, and to minimize the need for human sorters. For example, U.S. Pat. Nos. 4,257,218, 4,335,570, and 6,257,978 all disclose harvesting machines utilizing at least one form of agitating device (such as vibrating shaker heads or conveyor belts) to dislodge tomatoes from the vines. Several harvesting machines, such as those disclosed in U.S. Pat. Nos. 6,257,978 and 6,033,305, also utilize forced air pressure systems to further remove dirt and debris.
Unfortunately, larger is not always better. While wider and larger machines are generally capable of harvesting and processing a higher volume of vine-borne crops, many road and/or field situations make it impossible or impracticable to use or bring these large machines in to perform the desired harvesting. Such machines are also more difficult to maneuver. Such limited maneuverability may require the machine operator to spend additional time repositioning the machines to process each row of crops, or cause the machines to inadvertently trample one or more rows. In addition, larger machines tend to weigh more, and the added weight not only affects maneuverability (e.g. turning), it also makes the larger, heavier machines unusable in moist or muddy fields where they tend to bog down. It is therefore desirable to provide a smaller scale machine that is capable of harvesting larger volumes of vine-borne crops.
In addition, the design of many existing large and small-scale machines may cause damage to the fruit by imparting numerous drops and/or turns during processing. Many machines require the fruit to drop a distance of several feet over the course of processing through the machine, and to make several turns during the process. Each drop and each turn provides another point where the fruit may be damaged, so it is desirable to minimize the number and/distance that the fruit drops through the machine, and to minimize the number of turns the fruit makes as it travels through the machine.
Effective separating and sorting of harvested fruit is also important. More efficient removal of dirt, vegetation, trash and debris as well as more accurate sorting of fruit is possible when the harvested materials are widely dispersed, and not bunched together. Another unfortunate side effect of machines in which the fruit makes multiple turns is that the fruit and associated trash and debris tends to bunch together. Rather than the fruits being evenly spaced upon the conveyors (so that they may be easily examined and processed), these comers cause the fruits to become crowded as they are transported onto an intersecting conveyor sometimes forming windrows, making them more difficult to inspect and sort. This bunching makes removal of the trash and debris more difficult, and once removed, the bunching of the harvested fruit makes sorting more difficult as well. Furthermore, each turn involves a drop from one conveyor to another, risking additional damage to the fruit, and requiring more maintenance and cleanup from breakage. Transverse turns also tend to increase the overall width and size of the harvester machine. All of these consequences make it even more desirable to minimize the number of turns the fruit makes as it travels through the machine.
Several variations of cleaning systems for removal of dirt, vegetation, trash and debris have been implemented in existing machines, each with their own drawbacks. Suction fan systems used on some harvesting machines tend to be expensive, noisy, prone to plugging in wet conditions, at times unreliable, and need significant power. Many machines developed to harvest tomatoes in wetter climates do not utilize suction fans on the harvester for these reasons. Machines which use only a blower for removal of dirt, vegetation, trash and debris suffer from problems related to inadequate space for the air to vent and drop out this refuse, making it difficult to control where all the refuse is going. In many cases, the refuse winds up settling back onto the freshly harvested crop, defeating the purpose of the cleaning blower. On some foreign machines, this problem is solved by placing the blower at the rear of the machine, allowing the blown refuse to vent out the rear. However, it is preferable to be able to clean the crop before it reaches the rear of the machine, to allow room for manual and electronic sorting at the rear of machine. Otherwise, the crop stream would need to change directions in order to come back up the side of the machine for sorting. This would add to the width and bulk of the machine, making it larger and less maneuverable.
It is therefore desirable to provide a small-scale vine-borne crop harvesting machine capable of processing a large volume of crops that is usable in narrow, wet field situations where larger machines would bog down. It is further desirable that dirt, vegetation, trash and debris be effectively removed early in the harvesting process so that the sorting of crop on the machine may be accomplished at or near the rear, to avoid adding width and bulk to the machine.